The woman, 34, entered a Louisiana hospital and complained of pain and redness on her right forearm. The patient later admitted that a puncture wound on the forearm was from a needle.

After being questioned by doctors, the patient said she had injected herself with the chemicals at a party two days prior. Her condition seemingly improved after doctors gave her antibiotics, but she was rushed to surgery after increased redness, drainage and inflamed and swollen skin. Upon surgery, doctors discovered a flesh-eating bacteria moving so quickly that they could see it killing tissue around the injection site. Left with little choice, the doctors amputated her right arm and shoulder in addition to stripping away any dead muscle.

The final diagnosis was a necrotizing fasciitis, a rare infection caused by streptococcus bacteria. Patients with such infections often require surgery within a day of admission in order to survive, another study said.

Dr. Russell Russo, a third-year orthopedic resident at the Louisiana State University Health Sciences Center, was the lead author of the case report. Russo and the other authors of the report were worried that the growing popularity of illicit bath salts could cause a rise in the deadly infections. They also warned other emergency department health staff to pay close attention when patients are admitted to emergency rooms with similar skin infections caused by injections.

Last fall, the federal Drug Enforcement Agency banned three chemicals used to make similar "bath salts." But Russo and his colleagues warned other emergency department health workers to be careful when patients show up with skin infections after injections.

“The best treatment is prevention with public, street-based education and early detection,” Russo wrote.